Current Issue : October-December Volume : 2026 Issue Number : 4 Articles : 5 Articles
For physical modeling in coastal and ocean engineering, active absorption is essential to mitigate secondary reflections and maintain the integrity of the target wave field. Active absorption is primarily achieved through the design of frequency-domain filters. This study presents the frequency-domain expressions for the transfer functions of the wave surface in front of the wave paddle and the displacement of the wave paddle under a twodimensional active absorption mode, and analyzes and processes the low-frequency and high-frequency components. Combining a weighted least-squares algorithm, a filter design scheme based on weighted iterative automatic optimization is proposed. Using the theoretical wave paddle displacement without reflection absorption and the filter-calculated displacement as error metrics, this method automatically designs optimal filters for target operating conditions without manual intervention. To validate the active absorption performance of the proposed filter design algorithm, a two-dimensional frequency-domain active absorption wave-making model was developed based on the Fluent dynamic mesh module and user-defined functions (UDFs). Numerical simulations were conducted for both regular and irregular wave active absorption. The results demonstrate that this method achieves significantly better active absorption performance compared to existing active absorption approaches....
Conventional color electronic books and commercial advertising displays typically employ multilayer liquid crystal structures, in which light reflection and transmission are controlled to generate color images. In this study, a novel reflective bistable cholesteric liquid crystal display device was developed to simplify fabrication and increase image sharpness. The fabricated dual-frequency bistable liquid crystal device exhibits stable opaque focal conic states and transparent planar states after a single switching cycle, and no additional energy is required to maintain either state. These results demonstrate the significant potential of dual-frequency bistable liquid crystal devices for energy-efficient smart windows, electronic books, and optical components, providing new directions for the development of future energy-saving technologies....
Strain-engineered transition-metal dichalcogenide nanobubbles are promising platforms for quantum emission, as revealed by recent experimental observations. In this work, we present an ab initio investigation of MoS2, WS2, MoSe2, and WSe2 nanobubbles, linking their structural and electronic properties to predictions of their optical activity. Inflating forces yield tunable geometries with nonuniform, apex-concentrated strain, which is sensitive to material rigidity. Strain modifies band gaps and universally induces non-dispersive valence states, exhibiting composition-dependent wavefunction character, as revealed by an in-depth analysis of band structures and orbital contributions. Crucially, transitions from these apex-localized valence states are predominantly dark. This characteristic is attributed to their localization at the Γ-point, inhibiting transitions to the lowest unoccupied states that reside at the K-valley. While revealing that the herein considered sub-10-nm nanobubbles fall short as single-photon emitters, our findings provide essential understanding of the structure-property relations in emerging quantummaterials, providing robust design rules to optimize their characteristics for novel quantum applications....
Pd-decorated Janus ZrSSe monolayers provide a promising platform for adsorptioncoupled electronic modulation in two-dimensional materials. Using first-principles density functional theory, we systematically investigate the structural stability, electronic properties, and adsorbate-induced electronic response of Pd-modified Janus ZrSSe. The results show that Pd is most stably anchored at the hollow site on the S-terminated surface, with a formation energy of −1.45 eV, while substitutional incorporation remains energetically unfavorable even after HSE06 refinement. Compared with pristine ZrSSe, Pd decoration markedly strengthens the interaction with adsorbates, leading to strong chemisorption for CO (−1.026 eV) and C2H2 (−0.748 eV), whereas H2 remains comparatively weakly bound (−0.258 eV). Electronic-structure analysis reveals that CO induces the most pronounced perturbation because of strong orbital hybridization between Pd 4d states and C/O 2p states, resulting in the largest band-edge modulation among the three adsorbates. More importantly, biaxial strain provides an effective external degree of freedom for continuously tuning the electronic structure: tensile strain widens the band gap, whereas compressive strain systematically narrows it and ultimately drives a semiconductor-to-metal transition at sufficiently large compression. These findings establish Pd-decorated Janus ZrSSe as a strain-tunable electronic material in which adsorption, orbital hybridization, and bandedge evolution are intimately coupled, offering fundamental insights into controllable electronic modulation in polar two-dimensional systems....
Terahertz (THz) bands are critical for next-generation wireless fronthaul/backhaul applications. However, they face a fundamental coverage range limitation due to low emission power, severe path loss, and poor receiving sensitivity, especially in photonics-assisted THz systems beyond 300 GHz. To address this limitation, we develop a 335 GHz continuous-wave traveling wave tube amplifier with an output power close to 4W and a gain of over 50 dB, and construct a novel yet simple diversity receiving scheme to improve the receiving signal-to-noise ratio by ~3 dB. Through hybrid photonic–electronic synergy, combining photonics-assisted THz generation, high-power THz amplification, and spatial diversity reception, a record-breaking kilometer-scale THz wireless communication at 335 GHz—a highly challenging atmospheric window—is demonstrated. We first achieve a net rate of 27.84 Gbit s−1 over a 2.2 km wireless link—yielding an unprecedented rate–distance product of 61,248 Gbit s−1 ∙m—beyond 300 GHz to the best of our knowledge....
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